A number of filters are available for filtering water, but a commonly used filter employs particles of activated carbon which capture contaminants on the surface of the carbon. Over a period of time, some of the contaminants on the surface are absorbed into the center of the particles, but eventually the activated carbon becomes saturated and must be either discarded or regenerated.
To a minor extent, the useful life of an activated carbon filter can be extended by backwashing to physically remove contaminants that have accumulated on top of the outer surface of the carbon. Backwashing, however, will not remove contaminants absorbed within the particles of activated carbon, nor will it remove contaminants which have been adsorbed on the surface of the particles. Traditionally, the regeneration of activated carbon requires the removal of the filter from the filter vessel and transporting it to a controlled furnace where the contaminants are oxidized while the carbon is left intact. Steam or super heated steam may also be used in conjunction with heat to strip away contaminants. Unfortunately, such processes also result in the loss of some portion (typically 5 to 15 percent) of the activated carbon such that after a number of uses, the filter must be discarded or reconstructed. Furthermore, such existing regeneration processes are labor intensive and require the existence of an off-site scrubbing facility.
It would be desirable to provide an apparatus and method for regenerating activated carbon without requiring the removal of the filter from the filter vessel.